1. Field
The present disclosure relates to managing power and in particular to managing power use in a data processing system. Still more particularly, the present disclosure relates to a method and apparatus for managing power use while increasing a processing capacity of a data processing system upon demand.
2. Description of the Related Art
Operations in a data processing system are performed using a processing unit. The operations performed may include, for example without limitations fetch, decode, execute, and write-back. The number of operations performed by the cores in the processing unit over a period of time can be referred to as processing capacity. The demand for processing capacity in a data processing system can vary over time. For example, a data processing system may experience higher demand for processing capacity on weekdays rather than on weekends. In another example, as a business grows the business may have an increased demand for processing capacity.
In certain situations, the frequency of the cores in the processing unit can be increased to increase processing capacity. A core is the part of the processor unit that performs the operations. The frequency of a processing unit is the number of clock cycles of the processing unit per second. A clock cycle is a period of time that a core in the processor unit takes to perform one operation. Thus, the cores in the processing unit may perform more operations per second when the frequency of the processing unit is increased.
In other examples, processing capacity may be increased with the use of additional cores in a processing unit. Often times, processing units include more than one core. For example, a processing unit having more than one core may be able to perform more than one operation at the same time.
However, increasing the frequency of the processor unit may result in an increase in an amount of power used by the processor unit. Additionally, adding cores may result in an increase in the amount of power used in the data processing system. When the use of power in the data processing system increases, the heat produced in the data processing system increases. The production of heat may cause the temperature of the devices in the data processing system to increase. When devices in the data processing system reach a certain temperature, the data processing system may not perform properly.
Accordingly, it would be advantageous to have a method and apparatus which takes into account one or more of the issues discussed above as well as possibly other issues.